# AI programs an insulin pump with a 24-hour basal rate profile that ignores circadian insulin sensitivity, causing nocturnal hypoglycemia in a Type 1 diabetic

- **ID:** `medical/insulin-pump-basal-rate-circadian`
- **Domain:** medical
- **Category:** config_error
- **Error Code:** `PUMP-BASAL-ERR-03`
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The AI set a constant basal rate (e.g., 0.8 U/h) across 24 hours, failing to account for the dawn phenomenon (increased insulin need 3-8 AM) and nocturnal insulin sensitivity (decreased need 12-3 AM), resulting in hypoglycemia at 2-3 AM.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Medtronic MiniMed 780G v3.2 | active | — | — |
| Tandem t:slim X2 v2.7 | active | — | — |
| Insulet Omnipod 5 v1.4 | active | — | — |

## Workarounds

1. **Program a multi-step basal profile: 12 AM-3 AM: 0.5 U/h, 3 AM-8 AM: 1.0 U/h (dawn phenomenon), 8 AM-12 PM: 0.8 U/h, 12 PM-6 PM: 0.7 U/h, 6 PM-12 AM: 0.6 U/h. Validate with 3-day CGM data.** (90% success)
   ```
   Program a multi-step basal profile: 12 AM-3 AM: 0.5 U/h, 3 AM-8 AM: 1.0 U/h (dawn phenomenon), 8 AM-12 PM: 0.8 U/h, 12 PM-6 PM: 0.7 U/h, 6 PM-12 AM: 0.6 U/h. Validate with 3-day CGM data.
   ```
2. **Use the pump's built-in 'Basal Pattern' feature to create a 'Night Safe' pattern with reduced rate 12-3 AM. Set low-glucose suspend threshold at 70 mg/dL. Train patient on pattern switching.** (85% success)
   ```
   Use the pump's built-in 'Basal Pattern' feature to create a 'Night Safe' pattern with reduced rate 12-3 AM. Set low-glucose suspend threshold at 70 mg/dL. Train patient on pattern switching.
   ```
3. **Implement an algorithm in the pump management software that adjusts basal rates based on historical CGM data and circadian models. Example: 'AutoBasalCircadian' script that analyzes 14-day glucose patterns.** (80% success)
   ```
   Implement an algorithm in the pump management software that adjusts basal rates based on historical CGM data and circadian models. Example: 'AutoBasalCircadian' script that analyzes 14-day glucose patterns.
   ```

## Dead Ends

- **** — Uniform reduction may still cause nocturnal hypoglycemia if the rate during 12-3 AM is still too high, and may cause daytime hyperglycemia. (70% fail)
- **** — This ignores the dawn phenomenon; the rate may be too low for 3-8 AM, causing hyperglycemia upon waking. (65% fail)
- **** — This removes a critical safety feature that can prevent severe hypoglycemia; the root cause (incorrect basal profile) remains unaddressed. (90% fail)